Magnesium alloy



Patented Feb. 24, 1942 MAGNESIUM ALLOY Arthur Burkhardt, BerlinLichterfelde, and Richard Knabe, Berlin-Zehiendorf, Germany, assignorsto Georg Von Giesches Erben, Breslau, Germany, a corporation of GermanyNo Drawing. Application November 9, 1939, Serial No. 303,613. In GermanyDecember 17, 1938 4 Claims.

Our invention relates to a magnesium alloy, and more especially to analloy oi. the type described in U. S. Patent 2,159,964, for Magnesiumalloy, patented May 30, 1939.

In this patent, a magnesium alloy has been described that contains 2 to6% bismuth, 0.5 to 3% cadmium, 1 to 5% aluminium, and 1 to 3.5% zinc.The remainder is substantially all magnesium. The phrase substantiallyall magnesium is intended to include magnesium and magnesium with minoramounts of customary impurities and auxiliaries. Such auxiliary alloyingelements are, for instance, 0.1 to 2% each of manganese, calcium,silicon, or one of the metals of the iron group (iron, nickel, andcobalt) separately or collectively.

,Such and other auxiliaries are usual in magnesium alloys and they donot influence the characteristic properties of our novel alloys.

Investigations with alloys of the typedescribed in the said U. S. patenthave demonstrated that their properties can be improved by certain ad,-ditions.

According to our invention, magnesium alloys contain 2 to 6, preferably4 to 5% bismuth, 0.5 to

preferably about 3% zinc, and about 0.1 to 5% silver, the remaindersubstantially all magnesium.

Thus, it has been found that addition of silver at the rate of 0.1 to isfavorable.

Silver-containing'magnesium alloys have 8.1-

ready been developed in England by the National Physical Laboratory, andmagnesium alloys of high tensile strength have been produced by addingsilver, but the ductility of these alloys Our novel silver-containingmagnesium alloys are superior to those according to the said U. S.

patent in that they can beheat treated due to the addition or silver,and that their workability is much improved. In the working of thealloys according to the said patent, it had been found that they do notwork quite satisfactorily, and

this drawback is eliminated by our invention. Furthermore, it has beenfound that inmany cases it is desirable to increase the zinc content ofthe alloys according to the said U. S. patent beyond 1 to 3.5%, and upto about 7%. In this manner the tensile strength is reduced slightly,viz, to 34to 36 kg. per sq. mm. but the elongation rises to about 24 to26%. Alloys of this kind are employed if maximum tensile strength isless important than high elongation.

Such an alloy according to the invention contains, in addition to thepercentages of bismuth, cadmium, and aluminium indicated, 1 to 7% zincandabout 0.1 to 5% silver, remainder substantially all magnesium.

In the following tabulation, some examples of alloys according to ourinvention are given, it being understood that for all alloys in thetabulation the remainder is substantially all magnesium as definedabove, that is, magnesium with or without the aforesaid minor amounts ofcustomary impurities and/or auxiliaries.

We claim: i

from traces up to 7% zinc, from a small but effective' amount up to 5%silver, and a remainder substantially all of magnesium with customaryadditions and impurities.

2. A light metal alloy containing 1m 5% aluminum, 2 to 6% bismuth, 0.3to 3% cadmium, 1 to 7% zinc, 0.1 to 5% silver, and a remaindersubstantially all of magnesium with customary additions and impurities.

3. A light metal alloy containing 2 to 4% aluminum, 4 to 5% bismuth, 0.5to 3% cadmium, 1 to 3.5% zinc, 0.1 to 5% silver, and a remaindersubstantially all of magnesium with customary additions and impurities.4. A light metal alloy containing about 2to 4% aluminum, 4 to 5%bismuth, about 2% cadmium,

about 3% zinc, 0.1 to 5% silver, and substantially all magnesium to makeup AR'I'HUR BURKHARDT.

RICHARD KNABE.

